After a few hours of detention, Istanbul police have released a man who was one of the last known people to contact American woman Sarai Sierra before she went missing Jan. 21, Doğan news agency has reported. Other witnesses may also be interrogated in the investigation, the authorities said, according the report.

The man, who identified himself to Sierra on social media
sites as “Taylan,” was taken into custody after being questioned yesterday by
authorities. The man reportedly told police during his interrogation that the two
did not meet Jan. 21, despite planning to do so, daily Hürriyet has reported.

“We did not meet that day, but we had met before,” Taylan
said, adding that he had first met Sierra online four months ago.

The interrogation did not take place at a police station
due to a specific request made by the witness.

Earlier
reports claimed “Taylan” had arranged to meet Sierra by Galata Tower in
Beyoğlu on Jan. 20. Chat transcripts between him and Sierra, which led
police to discover his identity, were uncovered when Sierra’s husband,
Steven Sierra, turned his wife’s Facebook and Twitter correspondences
over to police in an attempt to better track her activities during her
stay. Sierra had been in contact with four Turkish citizens via the
social media websites.

Police think there is a good chance Sarai Sierra, an American woman who has been missing in Istanbul since Jan. 21, is still alive after discovering her U.S. phone was activated twice since she was reported missing, according to daily Sabah.

Sierra reportedly made a call using a Skype application on her American phone Jan. 30, nine days after she reportedly went missing. The woman’s phone was turned on once again yesterday, daily Sabah has reported.FBI, Turkish police share intelligence on missing woman

Turkish police are pursuing their collaboration with the Federal Bureau of Information (FBI) to find Sierra. The real identity of "Taylan" has been uncovered and transmitted to the Turkish police by the FBI, Doğan news agency reported yesterday.

Witnesses claim to have seen Sierra

Meanwhile, members of the public have contacted a foundation for missing people claiming to have seen Sierra before her disappearance, according to the head of the association.

"Some people have come and said they saw [Sierra] a week ago," Zafer Özbilir, the president of the Foundation for Relatives of Missing Persons (YAKAD), told the Hürriyet Daily News today, adding that the organization was directing such people to the police.

Some said they saw her taking photos over the Galata Bridge over Istanbul’s Golden Horn, he said. YAKAD is aiding in the search to locate the 33-year-old mother of two.

Sierra was supposed to return to New York on Jan. 22 but never boarded the plane in Istanbul, according to airline officials. Members of YAKAD launched a campaign to support the search for Sierra while drawing attention to the many missing-person cases in Turkey.

Traveling around in a bus they call “the bus of hope,” YAKAD members are currently distributing Sierra’s picture and details of her last-known whereabouts to help speed up the process. The bus is covered in photos of missing people, and its activities have helped resolve nearly 900 cases in the past.

Özbilir, who is also a relative of a lost person, said some 3,000 adults have gone missing only recently, adding that searching for Sierra was also helping to publicize their mission.

New footage surfaces

Footage of Sierra walking around Sultanahmet and Taksim surfaced yesterday, and police forces have been looking into the stores visited by Sierra.

New footage of the woman as she was entering the airport while traveling to Amsterdam from Istanbul was also released today. Three days after renting a room in Istanbul on Jan. 12, Sierra traveled to Amsterdam and Munich, Anatolia news agency quoted sources as saying. She returned to Turkey on Jan. 19.

The woman’s room in a Tarlabaşı house reportedly cost her 222 euros, while her expenses through her stay in Turkey, including the trip to the Netherlands and Germany, totaled over $10,000.

The owner of the house in which Sierra was staying said he had not seen the woman since Jan. 20, Doğan news agency reported.